Assist. Prof. Dr . Özge İNAL Macromolecules

Macromolecules

Assist. Prof. Dr. Özge İNAL

Spring; 2020

Polymer:

It is a high molecular weight compound, which is

formed by connecting the same or different atoms

more or less regularly with chemical bonds.

Monomer:

It is a large number of simple repeating units that

form polymers. Materials such as cellulose, starch,

gelatin, natural rubber are also known as natural

polymers and are made up of simple, repeated units.

Macromolecule:

High molecular weight compounds in the complex

structure described above are generally termed as

macromolecules.

Upon contact of the polymers with the liquids,

dissolution or gel formation is observed.

When a polymer is placed in the solvent, small

solvent molecules are diffused into the polymer

and the polymer is swollen.

Natural

macromolecules

Acacia gum

Tragacanth

Gelatine

Alginic acid

Starch

Agar

Pectin

 It is mixture of purified protein fractions

of animal collagen.

 consist of amino acids joined together by

amide linkages to form linear polymers.

Gelatin

(gelatinum)

Gelatin may be two types, Type A gelatin :

 is obtained by digestion with dilute acids

from the pig's pound.

 partial acid hydrolysis

 The isoelectric point is pH 3.8-6.

Type B gelatin:

 Raw ossein or leather is obtained by

neutralizing CaOH₃

 partial alkaline hydrolysis

 The isoelectric point is pH 5-7.4.

Used as: coating agent, film former, gelling agent, suspending agent, tablet binder, Ovule base Capsule material viscosity increasing

 It is extracted from brown sea algae

(Laminaria sp.)

 Its structure consist of mannuronic

and gluronic acid polymers.

Alginic acid

Sodium alginate

Orally,

• Tablet /capsule binder or disintegration agent • Hydrophilic matrix material in controlled

release

• Antiacid (Ex. gaviscon) Topically,

 Suspending agent and/or thickening agent in creams pastes and gels

 It is obtained from corn, wheat,

potatoes and rice.

 The structure contains amylose

(soluble) and amylopectin (insoluble,

swollen) polysaccharides.

 White powder. Insoluble in cold

water, swell in hot water (~ 70 ° C),

partially soluble at 100 ° C.

 It is used in tablets, capsules,

cachets and in topical dosage forms,

 Emollient in egzema (glycerine

ointment)

 Used in iodine toxicity, diarrhea

therapy (as rice musilage)

Starch

Semi synthetic

Macromolecules

Cellulose types

 Microcrystal cellulose (Avicel)  Carboxymethyl cellulose

 Methyl cellulose  Ethyl cellulose

 Hydroxy propyl cellulose

 Hydroxy propyl methyl cellulose  Sodium carboxy methyl cellulose

 Obtained from cellulose by methylation

in alkaline medium.

 It's white powder.

 It swells in cold water and forms a

colloidal dispersion. Insoluble in hot water and alcohol.

 It has bulk laxative therapeutic effect .  It is used in tablets as binder/coating

agent/disintegrant

 In oral liquids, suspensions, creams and

gels.  In ophthalmic preparations.  Types: A4MP 4000 mPa.s A15-LV 15mPa.s A15CP 1500mPa.s A4CP 400mPa.s

Methyl cellulose

(methocel)

 It is obtained by reaction with NaOH

solution.

 Odorless, tasteless, creamy white colored

fibrous or granular powder.

 It is soluble in cold water and gives a

viscous colloidal solution.

 Different types of viscosities are found (100

- 100000 mPa.s).

 It is used in tablets, topical formulations

and in eye drops

Ex. Tears Naturale Free / Alcon

In tablets,



it is used as binder and film coater



used to prepare a matrix tablet to provide sustained/

prolonged release.

In topical formulations,



Stabilizer



suspending agent,



viscosity enhancer,



emulsion agent.



Partly used as ophthalmic. Because it gives a clearer

solution than MC, it enters the eye drop and artificial tear

composition (0.5-1%).

Synthetic

macromolecules

 Polyvinyl alcohol

 Polyvinyl pyrrolidone

 Carbopol

 Poloxamer

 Acrylic acid polymers

 White, acidic, fluffy, hygroscopic

dust.

 High MW

 Crosslinked polymers,

 It is bioadhesive and can be used

tablets as binder,

 In topical formulations as

emulsifyer, suspension agent or

gelling agent.

 Can be used as controlled release

agent

Carbopol

(carbomer)

 obtained by hydrolysis in alcohol and mineral

acid or alkali catalysis in methyl acetate.

 It is used in topical, ophthalmic dosage

forms (artificial tears) and contact lens solutions and oral dosage forms.

MW: *200000 (high viscosity), *130000 (medium viscosity), *30000 (low viscosity)

Polyvinyl

alcohol (PVA)

 stabilization agent in emulsions

used in artificial tear and contact lens solutions

 microspheres,

 coating agent, lubricant in oral dosage forms

 patch backing material in transdermal therapeutic systems

 It is a creamy or white colored, odorless,

hygroscopic powder.

 Soluble in water and alcohols.  It can be used as

• carrier for drugs (10-25 %), • dispersing agent (up to 5%), • eye drops (2-10 %),

• suspension agent (max 5%),

• tablet binder/diluent or coating agent (0.5-5%)

Polyvinyl pyrrolidone (PVP)

(collidon, povidone)

Can be defined with “K” value due to MW and viscosity characteristics

K12 MW 2500; 1.3-2.3 mPa.s K17 MW 10000; 1.5-3.5 mPa.s K30 MW 50000; 5.5-8.5 mPa.s K90 MW 1000000; 300-700 mPa.s